Portable elevating mechanism



Sept. 13, 1966 P. A. LEDUC 3,272,286

PORTABLE ELEVATING MECHANISM Filed Aug. 24, 1964 5 Sheets-Sheet 1 INVENTGR.

F15 3... Phigip A L1.=duc" Sept. 13, 1966 P. A. LEDUC 3,272,286

PORTABLE ELEVATING MECHANISM Filed Aug. 24, 1964 5 Sheets-Sheet 2 I INVENTOR.

Sept. 13, 1966 P. A. LEDUC 3,272,286

PORTABLE ELEVATING MECHANI SM Filed Aug. 24, 1964 5 Sheets-Sheet 5 1 IN VENTOR.

Unite States Patent 3,272,286 PURIABLE ELEVATING MECHANISM Philip A. Leduc, Carlisle Ave., Turners Falls, Mass. Filed Aug. 24, 1964, er. No. 391,377 6 Claims. (Cl. 187-2) This invention is concerned with a lifting mechanism which has been conceived for the purpose of assisting construction workers in the installation of dry-wall sheets, plaster board, and the like, but which device has many other uses relative to the raising and holding of materials at various heights.

More particularly, this invention is an apparatus of the character described having means for moving the apparatus to a pre-determined location and having raising means for lifting large sheets of material to various heights within a predetermined distance.

It is the object of this invention to provide a portable apparatus that may be used within the rooms of a house or building.

It is an additional object of the within invention to provide a portable apparatus that has an expandable mechanism that rises vertically to a pre-determined height.

It is yet a further object of this invention to provide a portable apparatus that is light in weight and can be carried easily in a light-weight truck or the like.

It is still another object of the within invention to provide a lifting mechanism that is easily operable by one person.

It is yet a further object of the within invention to provide a novel transmission system for operating the mechanism.

It is an additional object of the within invention to provide an inexpensive and new type of locking means for preventing the lift mechanism from slipping.

It is yet a further object of the within invention to provide an inexpensive and novel cable arrangement for controlling the elevation of the expandable members of the device.

These objects and features of the invention are obtained by a frame assembly which is mounted on wheels. Within the frame assembly is mounted the elevating mechanism along with the supporting members attached thereto. Connected to the frame is a transmission system for causing the elevating mechanism to move up or down.

The novel features of the invention will be more readily understood from the following description which should be taken together with the accompanying drawings in which a particular embodiment of the invention is disclosed and in which the separate elements and parts are designated by suitable reference characters in each of the views and in which:

FIGURE 1 is a front elevational diagrammatic View of the lift assembly in extended position.

FIGURE 2 is a side elevational diagrammatic view (locking towards the view of FIGURE 1 from the right) of the invention with the lift assembly in extended position.

FIGURE 3 is a perspective view of the frame portion of the device.

FIGURE 4 is an exploded perspective view of the lift assembly of the invention.

FIGURE 5 is a diagrammatic side elevational view of the lift assembly of FIGURE 2 in extended position showing the cable arrangement for the upper segment.

FIGURE 6 is a side elevational view of the cable arrangement of FIGURE 5.

FIGURE 7 is a diagrammatic elevational view of the lift assembly in extended position locking towards the right side of FIGURE 1 and showing the cable arrangement for the intermediate segment.

FIGURE 8 is an exploded view of the locking or braking mechnaism.

FIGURE 9 is an exploded perspective view of the transmission system connected to the elevating shaft.

In the drawing FIGURE 3 shows the portable frame 8. The frame 8 comprises four separate vertical L-frame members 16 as well as, interconnecting at the tops and bottoms thereof, the four horizontal L-fr-ame members 16. In order to maintain structural support there are diagonal braces 17 which are made of flat steel stock. These braces 17 connect the vertical and horizontal members diagonally at the lower portion of the frame as shown in FIGURE 3. There are four separate guides 44 each arising above the vertical member 16. These guide members 44 control the upper assembly when the expandable unit is in closed or retracted position, which shall be explained hereinafter. At the bottom of the assembly 8 as shown in the view of FIGURE 3 are the conventional casters 9. The casters 9 are connected in the conventional manner (by screws) just below each vertical frame member 16. Across the upper horizontal frame members 16 are horizontal support members 21. These members 21 act as guides for preventing the lower segment 7 of the expandable unit from turning.

The frame 8 of FIGURE 3 is shown in a front elevational view in FIGURE 1. In the view of FIGURE 1, the expandable elevating mechanism is shown in the expanded position diagrammatically within the portable frame assembly 8. A worm 14 is connected to a worm gear 15. A crank 11 is connected to the drive gear 10 which is connected to a driven gear 12. Vertically mounted and meshing with the transmission system described is a vertical shaft (threaded) 13. At 18 the worm gear 15 and shaft 13 move as one piece. The expandable mechanism consists of the members which are telescopic; that is, one within the other as shown in FIGURE 1 as the top member or segment 5, the intermediate member or segment 6, and the bottom member or segment 7. There is an arrow in FIGURE 1 indicated by the numeral 4 which shows the point at which the expandable member lifts. When the expandable members 5, 6, and 7 are in closed position; that is, 5 within 6 and 6 within 7, the top of 7 is at the location of the arrow 4. Atop member 5 is the work supporting frame 3, which consists of an L- shaped metal member similar to the members 16. The embodiment of FIGURE 1 discloses a sheet of plaster board material 2 being held against a ceiling 1 by the expandable mechanism 5, 6, and 7.

The view of FIGURE 2 discloses a side elevational view of the expandable mechanism holding a sheet of plaster board 2 against a vertical wall 28. In this view the driven gear end 46 (which is the end of shaft 45) and, the drive gear shaft 47 are shown. The worm shaft 45 can be seen in FIGURE 9. At the top of the upper member 5 of the expandable mechanism is the L-shaped member which is also referred to as a top frame member 3. There is, in addition, a frame member 29 for the side walls. Connected to the frame of the side walls 29 is a hook-shaped member 34. This consists of a rod 33 of about /8" diameter, shaped as shown in the drawing.

The expandable mechanism or assembly is shown in an exploded view in FIGURE 4. In addition to the components already referred to in the previous views, FIG- URES 1, 2, and 3, there is a drive gear supporting bracket 38 which is mounted below the drive gear end or shaft 46 and the drive gear shaft 47. The bracket 38 is mounted on floor plate 37. The L-shaped sections 31 (for holding 2 x 4s) are connected to the L-shaped member 16. There is a screw for clamp 32 for locking 2 x 4s.

Some of the details of the expandable mechanism are shown in the view of FIGURE 5. A sheave or flat pulley 22a is mounted within a slot in the floor plate 37. Connected to the sheave 22a is a cable 23a. At the end of cable 23a is a ball end 30a which secures the cable to the lower portion 43 of bottom member 7. In the embodiment shown in FIGURE 5 there are two screws 40. The screws 40 are inserted in the bracket 38 for securing bracket 38 to the floor plate 37. At 41 a vertical rail 35 is attached to the floor plate 37. There is a groove on base 43 that rides on the rail 35 as base 43 ascends or descends. A locking lever 24 is located on member 5 within the intermediate member 6, similar to lever 24a in member 7. Also on the interior of the intermediate member 6 are locking teeth, similar to teeth 25a in member 7. The locking lever 24 is mounted on a locking lever pivot 26 on member 5. A locking lever 24a is mounted on a locking lever 26a on member 6 (see FIGURE 7). There is also a locking lever sheave or flat pulley 27 which is in contact with the cable 23 in member 6.,

The view of FIGURE 8 discloses the details of the locking lever pivot 26, the locking lever sheave 27 and the locking lever 24 in a diagrammatic drawing which more clearly demonstrates the operation thereof, which will be explained hereinafter.

The transmission system is shown in the perspective in the exploded view of FIGURE 9. There is also shown in this view the screws 40 for attaching the supporting bracket 38 to the floor plate 37. A washer 19 circumscribes the lower part 49 of the shaft 13 above the cotter pin 20 in the counter bored opening 50 in the floor plate 37. In the view of FIGURE 9 the drive gear shaft 47 supports the drive gear 10. The shaft 47 is mounted on the support bracket 38. Meshing with the gear 10 is the driven gear 12 which is securely fastened to the shaft end 46 of the shaft 45. Worm shaft 45 is mounted in the end bearing 39 (see FIGURES 1 and 7). Mounted onto the shaft 45 is the worm shaft 14 which meshes with the worm gear 15. The worm gear 15 is mounted on the shaft 13. There is below the worm gear 15 a collar 48 mounted on the shaft 13 above the lower portion of the shaft 49 for maintaining the shaft 13 securely against the floor plate 37.

In operation, the crank 11 of the drive gear 10 is rotated. This may be performed by hand or motor. The rotation of the drive gear 10 imparts motion to the driven gear 12 which turns the worm shaft 45 which in turn operates the worm gear 15 which meshes with the worm shaft 14 at 18 and which causes the threaded shaft 13 to turn. When threaded shaft 13 turns, the expandable mechanism (5, 6, and 7) begins to rise. The bottom segment or member 7 is threaded to shaft 13 within the opening inside the base 43 of the member 7. As the member rises on the threads of 13, the cable 23, because of the cable ball end 30a, is also pulled upwardly.

The base 43 rises on the threaded shaft 13. The cable 23a then pulls on the sheaves or flat pulley 22a. As the base 43 rises, pulling the cable over the sheave 2241, each of the telescopic members, 6 and 7, are caused to move upwardly. This can be seen clearly in the views of FIG- URES 5 and7 with reference to the view of FIGURE 6. It is to be noted that there are two separate cables 23 or 23a. Cable 23 is fastened securely to the base 37 as shown in FIGURE 6 and the other cable 23a is fastened,

to the base 43 of member 7 as hereinafter explained. There is a separate pulley system for each segment. The lower segment 7 moves upwardly and downwardly on the threaded shaft 13. The intermediate segment 6 operates from the pull of the cable system which circumscribes the sheave 22a which is mounted in the base plate 37. The upper segment 5 operates from the pull of the cable 23 which is secured permanently in the base plate 37 as shown in FIGURE 6.

It perhaps may be more explicit and simple to describe the operation first of the intermediate segment 6 and subsequently the operation of the upper segment 5. When the threaded shaft 13 is rotated from the transmission system as already explained, the base 43 of member 7 is caused to move upwardly upon the threads thereof as already mentioned. The cable 2311 which is shown in FIGURE 7 is stretched out causing a pull on the sheave 22a which is located in the base 37 and the sheave 22a which is located on the intermediate member 6 (see FIG- URE 7) and lower sheave 22a. The higher the base 43 rises, the higher rises the intermediate segment 6 until there is no more distance between the upper two sheaves 22a. Actually, the pivot assembly which is shown in FIGURE 8 and, particularly, the locking lever 24 prevents the two sheaves 22 from contacting one another. This assembly is identical for cables 23 and 23a and is not shown in detail for each cable for that reason. This is the closest that these two sheaves can come together. In the view of FIGURE 7, they are shown still some distance apart. It is to be kept in mind that the sheave 22a in the base plate 37 does not move nor does the sheave 22a located in the upper portion of segment move relative to segment 7. The sheave 22a located below the lever 24a does move towards and away from the top of segment 7.

Similarly, the operation of the upper segment 5 is the same as the intermediate segment 6. Reference is made to the view of FIGURE 5 and lower sheave 22 which is located on the upper segment 5. The sheave 22 located at the bottom of segment 5 is drawn towards sheave 22 located at the top of segment 6 with the rise of the lower segment 7 and reaches a point where the lever 24 prevents them from making contact. This is the fullest extension that can be obtained of the expandable mechanism. It is also important to note that both sets of sheaves, as described, the ones located in the view of FIGURE 5 and the ones in FIGURE 7, are operating simultaneously as the threaded member 13 is turning inside of the base 43 causing the base 43 and the lower segment 7 to rise.

A small motor of the electrical type may be used instead of the crank. A slipping clutch may also be employed. Neither of these devices would by themselves prevent the expandable members from collapsing. However, in the embodiment shown, there are separate locking levers 24 and 24a located in each of the segments 6 and 7. The locking assembly as noted is shown in FIGURE 8 and is the same assembly shown in FIG- URE 5 (in the upper segment 5) and is the same assembly shown in FIGURE 7 (in the intermediate segment 6).

When the weight of the assembly, because of the force of gravity, starts to drop, the abutment end of the lever 24 catches the locking teeth 25 and 25a which are secured to the inside surface of the segments 5 and 6 just beneath the segment upon which the lever arm is attached. For example, within the lower segment 7 are the locking teeth 25a mounted on the interior thereof. The lever arm 24a is mounted on the locking lever pivot 26a on the outside surface of the intermediate segment 6. Therefore, when the lever arm 24 is in a horizontal position as shown in FIGURE 8, it will contact the teeth 23 which are mounted within the segment 7. Similarly, reference may be had from View of FIGURE 5 with a similar locking lever arrangement which is located on the outside of the upper end segment 5 and enables the upper segment 5 to lock in place on teeth 25 located on the inside of the intermediate segment 6.

As long as there is tension on the cables 23 and 23a, the sheaves 27 and 27a on the locking lever 24 and 24a will be resting against the cables 23 and 23a respectively. The tension of the cables 23 and 23a prevent the lever arm 24 or 24a from dropping to the horizontal. When the tension on cables 23 or 23a is released (only when the cable actually breaks) will the lever arms 24 or 24a drop to the horizontal. This is the feature of having this type of safety device upon the invention, since it is in a sense an insurance policy against a broken cable. Actually, the arm 24 or 24a can never go substantially below the horizontal because the arm 24 or 24a falls onto the shaft rotatably supporting the said pulley 22 or 22a between the pulley 22 or 22a and the bearing segment.

It is now readily understandable that a carpenter, ceiling worker or other skilled laborer can wheel this device into a room, place a piece of wall board or sheet rock material on the upper supports 16 and then cause the telescopic members 5, 6, and 7 to be raised. When the piece of material is flush with the ceiling, and without the assistance of anyone else, the carpenter or worker may nail or fasten the sheet material to the ceiling. This is shown in FIGURE 1.

Likewise, if one desired to mount a piece of paneling on a side wall, the same procedure can take place by the operation as shown in FIGURE 2.

When the telescopic members are desired to be retracted, then the transmission system is rotated in an opposite direction at 11. The upper two members 5 and 6 drop slowly into telescopic relationship, one nested within the other, while the bottom member returns to closed position completely enclosing the shaft 13 with its bottom 43 in close proximity to the base plate 37.

The upper structure 16 and 3 then falls into place within the guides 44.

In the embodiment shown, the telescopic members have a geometrical design of being square or rectangular in cross-section.

There would be no departure from the scope and spirit of the invention if the telescopic members were cylindrical and were within one another in a concentric manner. However, for the particular purposes for which this embodiment has been designed, the rectangular or square shaped telescopic members have the advantage of being stronger and more sturdy for a fixed arrangement, preventing slipping and lateral movement.

Certain dimensions in the drawings have been somewhat exaggerated to teach more clearly the disclosure. It is further contemplated that certain mechanical improvements can be employed to replace strut or frame members without departing from the spirit or the scope of the invention.

In consideration of the foregoing disclosure,

I claim:

1. An elevating device having a portable frame, an elevating mechanism within said frame, said elevating mechanism consisting of a plurality of telescopic members of various size cross-sections, one nested within the other, the largest being at the bottom, and the smallest being at the top, a threaded shaft means connected to the bottom telescopic member, a transmission system for turning said threaded shaft means, and a safety device for maintaining and securing said elevating mechanism at pre-determined fixed heights, a separate .pulley system for operating each of said other telescopic members and operating synchronously with the lowering or raising of the bottom member, said pulley system for operating the next largest member having a sheave mounted in a floor plate afiixed to the frame, a sheave mounted in the lowest portion of the next largest member, a sheave mounted at the top of and inside of the largest member in alignment with the other mentioned sheaves, a cable attached to the bottom of the largest member, said cable circumscribing the sheave in the base plate, said cable rising to the sheave at the top of the largest member, said cable circumscribing the last-mentioned sheave, said cable dropping to the sheave attached to the bottom of the next largest member, said cable circumscribing said sheave and rising to the top of the largest member where it is secured, whereby when said threaded shaft means rotates, said sheave attached to the bottom of said next largest telescopic member rises to proximate contact with the sheave mounted at the top of the largest telscopic member.

2. An elevating device having a portable frame, an elevating mechanism within said frame, said elevating mechanism consisting of a plurality of telescopic members of various size cross-sections, one nested within the other, the largest being at the bottom, and the smallest being at the top, a threaded shaft means connected to the bottom telescopic member, a transmission system for turning said threaded shaft means, and a safety device for maintaining and securing said elevating mechanism at predetermined fixed heights, a separate pulley system for operating each of said other telescopic members and operating synchronously with the lowering or raising of the bottom member, said pulley system for operating the smallest member having a sheave mounted at the bottom of the said smallest member and within the next largest member, a sheave mounted at the top of the next largest member in alignment with the aforementioned sheave, a cable attached to a base plate beneath the base of the largest telescopic member and beneath the transmission system, said cable passing through an opening in the largest telescopic member and circumscribing the sheave mounted at the top of the next largest member, said cable passing down and around the sheave mounted at the bottom of the smallest telescopic member, said cable passing from a said bottom sheave upwardly and secured in an opening at the top of the next largest member, whereby when said threaded shaft means rotates, said sheave mounted at the bottom of the smallest telescopic member rises to proximate contact with the sheave mounted at the top of the next largest member.

3. An elevating device having a portable frame, an elevating mechanism within said frame, said elevating mechanism consisting of a plurality of telescopic members of various size cross-section, one nested within the other, the largest being at the bottom, and the smallest being at the top, a threaded shaft means connected to the bottom telescopic member, a transmission system for turning said threaded shaft means, and a safety device for maintaining and securing said elevating mechanism at pre-determined fixed heights, a separate pulley system for operating each of said other telescopic members and operating synchronously with the lowering or raising of the bottom member, said pulley system for operating the next largest member having a sheave mounted in a floor plate affixed to the frame, a sheave mounted in the lowest portion of the next largest member, a sheave mounted at the top of and inside of the largest member in alignment with the other mentioned sheaves, a cable attached to the bottom of the largest member, said cable circumscribing the sheave in the base plate, said cable rising to the sheave at the top of the largest member, said cable circumscribing the last-mentioned sheave, said cable dropping to the sheave attached to the bottom of the next largest member, said cable circumscribing said sheave and rising to the top of the largest member where it is secured, whereby when said threaded shaft means rotates, said sheave attached to the bottom of said next largest telescopic member rises to proximate contact with the sheave mounted at the top of the largest telescopic member, said pulley system for operating the smallest member having a sheave mounted at the bottom of the said smallest member and within the next largest member, a sheave mounted at the top of the next largest member in alignment with the aforementioned sheave, a cable attached to a base plate beneath the base of the largest telescopic member and beneath the transmission system, said cable passing through an opening in the largest telescopic member and circumscribing the sheave mounted at the top of the next largest member, said cable passing down and around the sheave mounted at the bottom of the smallest telescopic member, said cable passing from a said bottom sheave upwardly and secured in an opening at the top of the next largest member, whereby when said threaded shaft means rotates, said sheave mounted at the bottom of the smallest telescopic member rises to proximate contact with the sheave mounted at the top of the next largest member.

4. An elevating device as recited in claim '1 wherein said safety device comprises a plurality of teeth mounted on the inside surface of the bottom member and on the inside surface of the intermediate member, a separate locking lever pivotally mounted on each of the upper members, each of said separate locking levers being mounted at the bottom of the intermediate member and at the bottom of the top member, respectively, means on each locking lever normally engaged by its associated cable to maintain the lever in a downwardly extending angular position out of engagement with its associated teeth, whereby on breaking or slackening of a cable, its associated lever will move to a horizontal position to engage said teeth thereby preventing the member to which it is attached from dropping below the particular tooth to which it is engaged.

5. An elevating device as recited in claim 2 wherein said safety device comprises a plurality of teeth mounted on the inside surface of the bottom member and on the inside surface of the intermediate member, a separate locking lever pivotally mounted on each of the upper members, each of said separate locking levers being mounted at the bottom of the intermediate member and at the bottom of the top member, respectively, means on each locking lever normally engaged by its associated cable to maintain the lever in a downwardly extending angular position out of engagement with its associated teeth, whereby on breaking or slackening of a cable, its associated lever will move to a horizontal position to engage said teeth thereby preventing the member to which it is attached from dropping below the particular tooth to which it is engaged.

6. An elevating device as recited in claim 3, said safety device comprising a plurality of teeth mounted on the inside surface of the bottom member and on the inside surface of the intermediate member, a separate locking lever pivotally mounted on each of the upper members, each of said separate locking levers being mounted at the bottom of the intermediate member and at the bottom of the top member respectively, means on each locking lever normally engaged by its associated cable to maintain the lever in a downwardly extending angular position out of engagement with its associated teeth, whereby on breaking or slackening of a cable, its associated lever will move to a horizontal posi tion to engage said teeth thereby preventing the member to which it is attached from dropping below the particular tooth to which it is engaged.

References Cited by the Examiner UNITED STATES PATENTS 95,952 10/1869 Taws 187-82 659,197 10/1900 Allen 187-82 1,280,090 9/ 1918 Schrottky 187-24 1,407,124 2/ 1922 Carr 187-9 1,606,101 11/ 1926 Russell. 1,813,595 7/ 1931 Abbe 187-85 2,291,180 7/ 1942 Wiesner 187-11 2,632,530 3/1953 Wagner 187-9 2,877,868 3/ 1959 Gunning 187-9 3,031,092 4/ 1962 Maskel 187-9 3,178,038 4/1965 Love 187-9 FOREIGN PATENTS 161,702 4/ 1921 Great Britain. 885,824 12/1961 Great Britain.

SAMUEL F. COLEMAN, Primary Examiner. 

1. AN ELEVATING DEVICE HAVING A PORTABLE FRAME, AN ELEVATING MECHANISM WITHIN SAID FRAME, SAID ELEVATING MECHANISM CONSISTING OF A PLURALITY OF TELESCOPIC MEMBERS OF VARIOUS SIZE CROSS-SECTIONS, ONE NESTED WITHIN THE OTHER, THE LARGEST BEING AT THE BOTTOM, AND THE SMALLEST BEING AT THE TOP, A THREADED SHAFT MEANS CONNECTED TO THE BOTTOM TELESCOPIC MEMBER, A TRANSMISSION SYSTEM FOR TURNING SAID THREADED SHAFT MEANS, AND A SAFETY DEVICE FOR MAINTAINDING AND SECURING SAID ELEVATING MECHANISM AT PRE-DETERMINED FIXED HEIGHTS, A SEPARATE PULLEY SYSTEM FOR OPERATING EACH OF SAID OTHER TELESCOPIC MEMBERS AND OPERATING SYNCHRONOUSLY WITH THE LOWERING OR RAISING OF THE BOTTOM MEMBER, SAID PULLEY SYSTEM FOR OPERATING THE NEXT LARGEST MEMBER HAVING A SHEAVE MOUNTED IN A FLOOR PLATE AFFIXED TO THE FRAME, A SHEAVE MOUNTED IN THE LOWEST PORTION OF THE NEXT LARGEST MEMBER, A SHEAVE MOUNTED AT THE TOP OF AND INSIDE OF THE LARGEST MEMBER IN ALIGNMENT WITH THE OTHER MENTIONED SHEAVES, A CABLE ATTACHED TO THE BOTTOM OF THE LARGEST MEMBER, SAID CABLE CIRCUMSCRIBING THE SHEAVE IN THE BASE PLATE, SAID CABLE RISING TO THE SHEAVE AT THE TOP OF THE LARGEST MEMBER, SAID CABLE CIRCUMSCRIBING THE LAST-MENTIONED SHEAVE, SAID CABLE DROPPING TO THE SHEAVE ATTACHED TO THE BOTTOM OF TH E NEXT LARGEST MEMBER, SAID CABLE CIRCUMSCRIBING SAID SHEAVE AND RISING TO THE TOP OF THE LARGEST MEMBER WHERE IT IS SECURED, WHEREBY WHEN SAID THREADED SHAFT MEANS ROTATES, SAID SHEAVE ATTACHED TO THE BOTTOM OF SAID NEXT LARGEST TELESCOPIC MEMBER RISES TO PROXIMATE CONTACT WITH THE SHEAVE MOUNTED AT THE TOP OF THE LARGEST TELESCOPIC MEMBER. 